Java Recycler类代码示例

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private int fixLayoutEndGap(int endOffset, Recycler recycler, State state, boolean canOffsetChildren) {
    int gap = this.mOrientationHelper.getEndAfterPadding() - endOffset;
    if (gap <= 0) {
        return 0;
    }
    int fixOffset = -scrollBy(-gap, recycler, state);
    endOffset += fixOffset;
    if (canOffsetChildren) {
        gap = this.mOrientationHelper.getEndAfterPadding() - endOffset;
        if (gap > 0) {
            this.mOrientationHelper.offsetChildren(gap);
            return gap + fixOffset;
        }
    }
    return fixOffset;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
public void onInitializeAccessibilityNodeInfoForItem(Recycler recycler, State state, View host, AccessibilityNodeInfoCompat info) {
    android.view.ViewGroup.LayoutParams lp = host.getLayoutParams();
    if (lp instanceof LayoutParams) {
        LayoutParams glp = (LayoutParams) lp;
        int spanGroupIndex = getSpanGroupIndex(recycler, state, glp.getViewLayoutPosition());
        if (this.mOrientation == 0) {
            int spanIndex = glp.getSpanIndex();
            int spanSize = glp.getSpanSize();
            boolean z = this.mSpanCount > 1 && glp.getSpanSize() == this.mSpanCount;
            info.setCollectionItemInfo(CollectionItemInfoCompat.obtain(spanIndex, spanSize, spanGroupIndex, 1, z, false));
            return;
        }
        int spanIndex2 = glp.getSpanIndex();
        int spanSize2 = glp.getSpanSize();
        boolean z2 = this.mSpanCount > 1 && glp.getSpanSize() == this.mSpanCount;
        info.setCollectionItemInfo(CollectionItemInfoCompat.obtain(spanGroupIndex, 1, spanIndex2, spanSize2, z2, false));
        return;
    }
    super.onInitializeAccessibilityNodeInfoForItem(host, info);
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private void ensureAnchorIsInCorrectSpan(Recycler recycler, State state, AnchorInfo anchorInfo, int itemDirection) {
    boolean layingOutInPrimaryDirection = true;
    if (itemDirection != 1) {
        layingOutInPrimaryDirection = false;
    }
    int span = getSpanIndex(recycler, state, anchorInfo.mPosition);
    if (layingOutInPrimaryDirection) {
        while (span > 0 && anchorInfo.mPosition > 0) {
            anchorInfo.mPosition--;
            span = getSpanIndex(recycler, state, anchorInfo.mPosition);
        }
        return;
    }
    int indexLimit = state.getItemCount() - 1;
    int pos = anchorInfo.mPosition;
    int bestSpan = span;
    while (pos < indexLimit) {
        int next = getSpanIndex(recycler, state, pos + 1);
        if (next <= bestSpan) {
            break;
        }
        pos++;
        bestSpan = next;
    }
    anchorInfo.mPosition = pos;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private void recycleViewsFromStart(Recycler recycler, int dt) {
    if (dt >= 0) {
        int limit = dt;
        int childCount = getChildCount();
        int i;
        if (this.mShouldReverseLayout) {
            for (i = childCount - 1; i >= 0; i--) {
                if (this.mOrientationHelper.getDecoratedEnd(getChildAt(i)) > limit) {
                    recycleChildren(recycler, childCount - 1, i);
                    return;
                }
            }
            return;
        }
        for (i = 0; i < childCount; i++) {
            if (this.mOrientationHelper.getDecoratedEnd(getChildAt(i)) > limit) {
                recycleChildren(recycler, 0, i);
                return;
            }
        }
    }
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private int fixLayoutStartGap(int startOffset, Recycler recycler, State state, boolean canOffsetChildren) {
    int gap = startOffset - this.mOrientationHelper.getStartAfterPadding();
    if (gap <= 0) {
        return 0;
    }
    int fixOffset = -scrollBy(gap, recycler, state);
    startOffset += fixOffset;
    if (canOffsetChildren) {
        gap = startOffset - this.mOrientationHelper.getStartAfterPadding();
        if (gap > 0) {
            this.mOrientationHelper.offsetChildren(-gap);
            return fixOffset - gap;
        }
    }
    return fixOffset;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
int scrollBy(int dy, Recycler recycler, State state) {
    int i = 0;
    if (!(getChildCount() == 0 || dy == 0)) {
        this.mLayoutState.mRecycle = true;
        ensureLayoutState();
        int layoutDirection = dy > 0 ? 1 : -1;
        int absDy = Math.abs(dy);
        updateLayoutState(layoutDirection, absDy, true, state);
        int consumed = this.mLayoutState.mScrollingOffset + fill(recycler, this.mLayoutState, state, false);
        if (consumed >= 0) {
            if (absDy > consumed) {
                i = layoutDirection * consumed;
            } else {
                i = dy;
            }
            this.mOrientationHelper.offsetChildren(-i);
            this.mLayoutState.mLastScrollDelta = i;
        }
    }
    return i;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private void recycleViewsFromEnd(Recycler recycler, int dt) {
    int childCount = getChildCount();
    if (dt >= 0) {
        int limit = this.mOrientationHelper.getEnd() - dt;
        int i;
        if (this.mShouldReverseLayout) {
            for (i = 0; i < childCount; i++) {
                if (this.mOrientationHelper.getDecoratedStart(getChildAt(i)) < limit) {
                    recycleChildren(recycler, 0, i);
                    return;
                }
            }
            return;
        }
        for (i = childCount - 1; i >= 0; i--) {
            if (this.mOrientationHelper.getDecoratedStart(getChildAt(i)) < limit) {
                recycleChildren(recycler, childCount - 1, i);
                return;
            }
        }
    }
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private int getSpanIndex(SpanSizeLookup spanSizeLookup, int spanCount, RecyclerView.Recycler recycler, RecyclerView.State state, int pos) {
    if (!state.isPreLayout()) {
        return spanSizeLookup.getCachedSpanIndex(pos, spanCount);
    }

    final int adapterPosition = recycler.convertPreLayoutPositionToPostLayout(pos);
    if (adapterPosition == -1) {
        return 0;
    }
    return spanSizeLookup.getCachedSpanIndex(adapterPosition, spanCount);
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private int getSpanSize(SpanSizeLookup spanSizeLookup, RecyclerView.Recycler recycler, RecyclerView.State state, int pos) {
    if (!state.isPreLayout()) {
        return spanSizeLookup.getSpanSize(pos);
    }

    final int adapterPosition = recycler.convertPreLayoutPositionToPostLayout(pos);
    if (adapterPosition == -1) {
        return 0;
    }

    return spanSizeLookup.getSpanSize(adapterPosition);
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
private void assignSpans(GridRangeStyle rangeStyle, RecyclerView.Recycler recycler, RecyclerView.State state, int count,
    int consumedSpanCount, boolean layingOutInPrimaryDirection, LayoutManagerHelper helper) {
    int span, spanDiff, start, end, diff;
    // make sure we traverse from min position to max position
    if (layingOutInPrimaryDirection) {
        start = 0;
        end = count;
        diff = 1;
    } else {
        start = count - 1;
        end = -1;
        diff = -1;
    }

    if (helper.getOrientation() == VERTICAL && helper.isDoLayoutRTL()) { // start from last span
        span = consumedSpanCount - 1;
        spanDiff = -1;
    } else {
        span = 0;
        spanDiff = 1;
    }

    for (int i = start; i != end; i += diff) {
        View view = rangeStyle.mSet[i];
        int spanSize = getSpanSize(rangeStyle.mSpanSizeLookup, recycler, state, helper.getPosition(view));
        if (spanDiff == -1 && spanSize > 1) {
            rangeStyle.mSpanIndices[i] = span - (spanSize - 1);
        } else {
            rangeStyle.mSpanIndices[i] = span;
        }
        span += spanDiff * spanSize;
    }
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
@Override
public void layoutViews(RecyclerView.Recycler recycler, RecyclerView.State state,
                        LayoutStateWrapper layoutState, LayoutChunkResult result, LayoutManagerHelper helper) {
    mTempLayoutHelper = helper;

    doLayoutView(recycler, state, layoutState, result, helper);

    mTempLayoutHelper = null;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
public int getColumnCountForAccessibility(Recycler recycler, State state) {
    if (this.mOrientation == 1) {
        return this.mSpanCount;
    }
    if (state.getItemCount() < 1) {
        return 0;
    }
    return getSpanGroupIndex(recycler, state, state.getItemCount() - 1) + 1;
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
public void onLayoutChildren(Recycler recycler, State state) {
    if (state.isPreLayout()) {
        cachePreLayoutSpanMapping();
    }
    super.onLayoutChildren(recycler, state);
    clearPreLayoutSpanMappingCache();
    if (!state.isPreLayout()) {
        this.mPendingSpanCountChange = false;
    }
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
void onAnchorReady(Recycler recycler, State state, AnchorInfo anchorInfo, int itemDirection) {
    super.onAnchorReady(recycler, state, anchorInfo, itemDirection);
    updateMeasurements();
    if (state.getItemCount() > 0 && !state.isPreLayout()) {
        ensureAnchorIsInCorrectSpan(recycler, state, anchorInfo, itemDirection);
    }
    ensureViewSet();
}
 

import android.support.v7.widget.RecyclerView.Recycler; //导入依赖的package包/类
View next(Recycler recycler) {
    if (this.mScrapList != null) {
        return nextViewFromScrapList();
    }
    View view = recycler.getViewForPosition(this.mCurrentPosition);
    this.mCurrentPosition += this.mItemDirection;
    return view;
}